Many devices which are operated by a motor need to be provided with a system for cooling the motor to prevent overheating thereof. Typical of such devices are appliances such as food blenders which may be used in domestic or commercial environments. In these devices, the rotating motor shaft is usually provided with a fan near the bottom thereof which draws cooling air into the motor housing and around the motor for subsequent discharge. However, the movement of this air, as well as the operation of the motor itself, presents a sometimes significant amount of noise which can be an irritant to the user as well as those nearby, such as the customers in a commercial establishment. The faster the air is moving, which is desirable for its cooling effect, the more noise is generated thereby.
As a result, efforts have been directed toward muffling or otherwise reducing the amount of noise generated by the air-cooled motor. One example of such is shown in U.S. Pat. No. 5,273,358. While the device shown in that patent, as well as other muffling devices, do reduce the noise created by the motor and the moving air, they do so at the expense of air flow. That is, in order to reduce the noise, the flow of air past the motor is decreased thereby deterring the cooling effect of the air.
Thus, the need exists for a system which can muffle or otherwise reduce the noise generated by a motor and its cooling air without detriment to the flow of air past the motor and, in fact, muffling the sound while at the same time increasing the air flow.